多项选择题
You are the network consultant from passguide.com. Do you know what attacks are software based attacks that disable your computer and attack user by e-mail?（）
A.Virus B.Worm C.Trojan D.Executable
单项选择题 How does a switch respond when it receives a message?（）
多项选择题 Which two Internet Protocol (IP) telephony devices are best categorized as infrastructure components? （）
单项选择题 What ensures that voice packets are given priority throughout the network so that conversations arrive intact?（）
